Safety guard for power presses



Sept. 18, 1951' w. H.

Roy 2,568,367

SAFETY GUARD FOR POWER PRESSEIS Filed Sept. 12, 1949 2 Sheets-Sheet 1uz'jZ f V zi g :4 a 4; 29 v INVENTOR. Z4 MLDRON ROY 27 A TTOR/VE Y Sept.18, 1951 w.

H. ROY

SAFETY GUARD FOR POWER PRESSES Filed Sept. 12, 1949 2 Sheets-Sheet 2Patented Sept. 18, 1951 OFFICE SAFETY GUARD FOR POWER PRESSES Waldron H.Roy, Oxford, Conn, assignor to William M. Goss, Jr., Waterbury, Conn.

Application September 12, 1949, Serial No. 115,205

1 Claim. 1

This invention relates to safety guards, and more particularly to aguard for protecting an operators hands against injury in presses,spotwelders, riveters, and other machines having reciprocating partswhich are potentially dangerous to the operator.

One object of this invention is to provide a guard of the above naturein which the operators hands will be removed from the danger zone at theproper time by a pair of sweep rods which have a positive operatingconnection with the reciprocating machine parts, whereby the operatorwill be protected during every cycle of the machine, whether said cycleis intentional on the part of the operator or otherwise.

Another object is to provide a safety guard of the above nature in whichthe sweep rods will be actuated by relatively short cam-operated levers,whereby a small intial movement of the machine parts will cause thesweep rods tov remove the operator's hands from the danger zone.

Another object is to provide a safety guard of the above nature which isreadily adjustable in accordance with different presses and to differentoperating conditions, and which will hold its adjustment againstaccidental changes.

A further object is to provide a safety guard of the above nature whichwill be simple in construction, inexpensive to manufacture, easy toinstall, compact, ornamental in appearance, very dependable inoperation, and eflicient and durable in use.

With these and other objects in view, there has been illustrated on theaccompanying drawings one form in which the invention may convenientlybe embodied in practice.

In the drawings,

Fig. 1 is a perspective view showing the improved safety guard as itwould appear when applied to one type of press.

Fi 2 is a plan view of the safety guard on an enlarged scale, showingadjacent portions of the press.

Fig. 3 is a front view of the same.

Fig. 4 is a side view of the same, the lower portions of the sweep rodsbeing broken away.

Fig. 5 is a front view of a modified cam plate which may be used foroperating the sweep rods.

Referring now to the drawings in which like reference characters denotecorresponding parts throughout the several views, the letter P indicatesa press of the type which has a frame I0 provided with a bolster plate Hand a pair of side pillars l2, l3, which embrace a subframe l4. Thesubframe I4 is provided with a pair of par- 2 allel vertical ways [5,[6, which slidably retain a dovetailed press gate l1 adapted to bevertically reciprocated in said Ways by means of operating mechanism 18when the latter is actuated by means of a pedal 19.

The improved safety guard is indicated generally by the numeral 20, andcomprises a pair of depending laterally-swingable sweep rods 2|, 22, theupper end portions of which are secured in a pair of angular blocks 23,24, respectively, by means of set screws 25.

The angular blocks 23, 24 are retained upon threaded outer end portionsof a pair of parallel horizontal shafts 26, 21 by means of a pair ofnuts 28, and are held against rotation with relation to said shafts bymeans of set screws 29.

The shafts 26, 21 are rotatably carried in aper-- tured bearing blocks30, 3| respectively having set screws 32 for securing said bearingblocks in laterally adjusted positions upon a square horizontalsupporting bar 33 embraced by the lower portions of said blocks.

In order to mount the supporting bar 33 in a stationary position whichis forwardly of the gate I! when the latter is at the upper end of itsstroke, provision is made of means preferably comprising a pair ofapertured brackets 34, 35 adapted to be attached to front side portionsof the subframe l4 by means of screws 36, said brackets having setscrews 3"! for adjustably securing a pair of The respective L-rods 38,39 have forwardly- I, projecting upper end portions 40, 4| to which apair of vertical rods or uprights 42, 43 are adjustably attached bymeans of angular apertured couplings 44, 45 having pairs of set screws46, 41 for securing said L-rods and said vertical rods respectively.

Opposite end portions of the horizontal supporting bar 33 are verticallyapertured and provided with horizontal set screws 48 so as to providevertically adjustable attachment of said bar to the vertical rods 42,43. Thus, it will be seen that the vertical rods 42, 43 and the L-rods38 are constructed and arranged to permit both horizontal and verticaladjustment of the supporting bar 33, as will be further describedhereinafter. However, it will be understood that other suitable bracketstructures may be employed for mounting the supporting bar 33 upon thepress P.

In order to operate the sweep rods 21, 22, the inner ends of thehorizontal shafts 23, 21 have laterally inwardly extending levers 49,5|], se-

it cured thereto by means of cross pins the effective length of saidlevers being relatively short as compared with the length of the sweeprods 2|, 22. The ends of the levers 49, 5B are provided withrearwardly-extending followers or cam rollers 52, 53 engaged in aU-shaped slot 54 in a vertical cam plate 55 which is secured to thefront face of the gate I! by means of screws 56.

It will be seen that the U-shaped slot 54 has a horizontal lower portion51 in which the cam rollers 52, 53 are disposed when the gate I1 is inits uppermost position and the sweep rods 2i, 22 are in adjacent orlowermost central positions.

The respective ends of the horizontal slot portion 51 are curvedupwardly and extend into steepl inclined or vertical end slot portions58, 59 which the cam rollers 52, 53 will enter when the gate l'ldescends to a lower position, with attendant outward swinging andseparating of the sweep rods 2|, 22.

It will thus be seen thatan initial downward movement of the gate I!will cause the'sweep' rods 2|, 22 to be swung rapidly in an outwarddirection as a result of the horizontal formation of the lower slotportion 5'! and the relative short ness of the cam levers 49, 55, and itwill also be seen that the subsequent further downward movement of thegate ll will merely cause the sweep rods 2|, 22 to be held stationary ornearly stationary in their outer positions as a result of the verticalformation of the slot end portions 55, 59.

The cam plate 55 may, of course, be modified so as to permit the safetyguard2il to be used upon presses having different lengths of stroke, orto cause the sweep rods 2|, 22 to swing outwardly during a relativelysmaller initial portion of the downward movement of the gate ll, onesuch modified cam plate being shown at 60 in Fig. 5.

The cam plate 60 is of generally the same construction as the cam plate55 and is provided with a U-shaped slot 6! having a horizontal lowerportion 62.

The slot 6|, however, is provided with relatively long verticallyextended end portions 63, 54, so as to accommodate the cam rollers 52,53 during a relatively long downward stroke of the gate [1, and alsoproviding for complete outward swinging movement of the sweep rods 2 l,22 during a relatively small initial portion of the downward stroke ofsaid gate.

Installation In installing the improved safety guard 25 upon a punchpress P, it will merely be necessary to drill and tap suitable holes toreceive the screws 36 and 56 in the subframe l4 and in the gate [1,respectively, no further alteration of said press being required. Thecam plate 55 will then be secured in place by means of the screws 55 andthe brackets 34, 35 will be attached to the subframe l4 b means of thescrews 35, so as to hold the cam rollers 52, 53 in operating positionwithin the cam slot 54.

Inasmuch as the L-rods 38, 59 are horizontally swingable for purposes ofadjustment, the utility of the safety guard 25 will not be limited byany specific width of the subframe 14, said L-rods 38, 39 being securedby the set screws 31 in such positions as to center the horizontalsupporting bar 33 opposite the raised position of the gate ll. Theangular couplings 44, 45 will be suitably adjusted inwardly or outwardlyupon the L-rods 38, 39 so as to locate the cam rollers 52, 53 in aproper vertical plane for effective operating relationship to the camplate 55, said couplings 44, 45 being secured by means of the set screws46.

Vertical adjustment of the supporting bar 43 will, of course, bepermitted by loosening the set screws 48, said adjustment being suchthat the short operating levers 49, 50, occupy horizontal positions whenthe gate I1 is in its uppermost position.

It will be understood that when the operating levers 49, 55arehorizontal, the sweep rods 2 I, 22 will be disposed in adjacentpositions which may be vertical as shown. However, if it is desired thatthe sweep rods 2 I, 22 be disposed eccentrically at one side of thecenter of the press when they are in their adjacent positions (as forexample to permit the operator to have better access to the press)xthesweep rods 2|, 22 may both be adjusted in the same lateral directionafter first loosening the set screws 29 and the nuts 28. It will also beunderstood that operation of the press will cause the sweep rods 2|, 22to swing across the front of the press, regardless of the location inwhich said sweep rods may be disposed when in their neutral or adjacentpositions.

Vertical adjustment of the sweep rods 2|, 22 will be permitted by theset screws 25, and will be such that the lower ends of the sweep rodswill be disposed adjacent the bolster plate II when said rods are intheir lowermost or vertical positions.

The speed and range of movement of the sweep rods 2|, 22 may be adjustedby moving the bearing blocks 39, 3| inwardly or outwardly upon thesupporting bar 33, the set screws 52 serving to hold said bearing blocksin their adjusted positions. The efiectof adjusting the bearing blocks30, 31 toward each other will be to increase the speed and range ofmovement of the sweep rods 2|, 22, while outward adjustment of saidbearing blocks will decrease the speed and range of movement of saidsweep rods.

The reason for this effect will be apparent when it is considered thatthe cam rollers 52, 53 are actuated only by the horizontal slot portion57 and the immediately adjacent curved slot portions.

Operation In operation, the operator may havefree access to the press ateither side of the sweep rods 2|, -2-2. When the press is put intooperation, the gate I! will start to descend and the sweep rods 2|, 22will immediately swing outwardly so as to remove the operators handsfrom the danger zone beneath the gate ll.

In practice, it has been found that the safety guard may be so adjustedthat the sweep rods 21, 22 will swing apart to approximately theirfullest extent after only initial downward movement of the gate ll.Further downward movement of the gate ll will cause little or no furtheroutward movement of the sweep rods 2!, 22, inasmuch as the cam rollers52, 53 will then be disposed in the vertical slot portions 58, 59.

-When the gate ll returns to its upper position, the sweep rods 2|, 22will swing toward each other to their relatively adjacent or neutralpositions so that the operator may again have free access to the press.

It will be noted that the sweep rods 2|, 22 have a positive operatingconnection with the gate ll, so that the safety guard will alwaysoperate when the press operates, and the operator cannot be caughtunawares by accidental repeating of the press cycle.

While there has been disclosed in this specification one form in whichthe invention may be embodied, it is to be understood that this form isshown for the purpose of illustration only, and that the invention isnot to be limited to the specific disclosure, but may be modified andembodied in various other forms without departing from its spirit. Inshort, the invention includes all the modifications and embodimentscoming within the scope of the following claim.

Having thus fully described the invention, what is claimed as new, andfor which is is desired to secure Letters Patent, is:

In a safety guard for a machine having a reciprocating member, a pair oflaterally swingable sweep rods, means for mounting said sweep rods independing positions in front of the path of said reciprocating member, apair of cam levers operatively connected to said sweep rods for swingingthe respective rods, and a cam plate adapted to be attached to saidreciprocating m m e and. hav g a slot. e e a e g with said cam levers,said slot having a portion disposed at right angles to the path of saidreciprocating member for swinging said cam levers, and ,a pair ofadditional slot portions which are disposed at angles to said firstmentioned slot portion for holding said cam levers during continuedmovement of said reciprocating member.

WALDRON H. ROY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

